1. Field of the Invention
This invention relates to a method of and a system for forecasting future orders in part inventory management, particularly to a method of and a system for forecasting future number of orders or demand of low-order-rate parts whose order rates have fallen below a predetermined level.
2. Description of the Related Art
In the manufacturing industry, numerous kinds of product parts (spare parts), such as parts for vehicles that have been sold to users, must be stocked for predetermined time periods and supplied in response to orders from dealers and users. At present, part inventories are ordinarily estimated by an expert who uses appropriate techniques to predict future number of orders.
Japanese Laid-open Patent Application No. Hei 11(1999)-7482 teaches a method that uses Monte Carlo simulation to project how much inventory should be stocked by intermediate suppliers in a distribution network.
Ordinarily, orders or demand for a part(s) are relatively active while the product is in production and for a while after production is discontinued but thereafter gradually decline, eventually reaching a rate of around one (one unit) per month.
While orders are brisk, the large number of transactions generates much transaction data that make projection of the optimum inventory level relatively easy. As orders decline, however, forecasting becomes increasingly difficult. At a low order rate, even an expert has difficulty predicting future number of orders with good accuracy.
The fact is, however, that parts whose order rates have become low make up the majority. In addition, low-order-rate parts pose incidental issues that require resolution, such as whether or not to discard the dies used to manufacture the parts.
Accurate forecasting is therefore desired with regard to end orders or demand (from users, dealers and so on) for parts, particularly low-order-rate parts. The method offered by the prior-art mentioned above is limited to use of Mote Carlo simulation for forecasting the optimum inventories to stock at intermediate suppliers based on end orders known beforehand.